The present invention relates to a device which uses a light beam to record or reproduce the image of a picture such as a photograph having half-tones (hereinafter referred to as "a half-tone picture or image" when applicable) on a photosensitive material.
More specifically, the invention relates to a device for recording a half-tone image by subjecting a light beam to binary (two-valued or ON-OFF) modulation and scanning it on a photosensitive material wherein half-tones are reproduced with high fidelity and high accuracy taking into account the characteristics of the photosensitive material employed, the density range of an original picture and, if necessary, the characteristics of a signal transmission system.
The present applicant has disclosed in U.S. patent application Ser. No. 214.815, filed Dec. 9, 1980 (corresponding to Japanese Patent Application No. 168565/1979) a system with which the image of a picture having half-tones can be recorded or reproduced by sampling input signals with the aid of sampling pulses. By applying to a semiconductor laser oscillator or the like pulses outputted during the sampling period with the number of pulses (pulse number) or pulse width controlled according to the levels of the input signals.
In order to further improve this system, an object of the present invention is to provide a recorder which reproduces the image of a picture with half-tones with high fidelity and high accuracy taking into account the characteristics of the photosensitive material employed, the density range of an original picture, and if necessary, the characteristic of a signal transmission system.